1. Field of the Invention
The present invention relates to a method and an apparatus for elevator group control by which an elevator system including a plurality of elevator cars and a plurality of destination floors are controlled.
2. Description of the Background Art
Recently, an elevator system including a plurality of elevator cars and a plurality of destination floors is equipped with a microcomputer to administer efficient and speedy allocations of elevator cars to hall calls produced at various destination floors, so as to improve the efficiency of elevator utilization and the quality of service.
Namely, in such an elevator system, when a hall call is produced at a certain floor, an elevator car which is most appropriate to respond to this hall call is selected from the plurality of elevator cars of the system, while the other elevator cars are prohibited to respond to this hall call.
More recently, a group controlled elevator system has been developed in which an elevator group control apparatus can perform the elevator car allocation control by gathering so called elevator car call response registration data regarding hall calls to which each elevator car has responded, so as to apprehend traffic demands among the floors of each building, and by utilizing these data to the elevator car allocation control, so as to account for a unique situation characteristic to each building. In this type of the elevator car allocation control, various evaluation characteristics are set up in accordance with the characteristics of each building, evaluation values for these evaluation characteristics are estimated, the evaluation values are multiplied by appropriate weight factors functioning as control parameters and then summed to obtain a total evaluation for each elevator car, and the most appropriate elevator car is selected from the plurality of elevator cars in accordance with the total evaluations obtained for the plurality of elevator cars.
However, because the relative importance of each of the evaluation characteristics for the elevator car allocation control changes radically depending on the traffic situation, so that ideally the control parameters have to be selected, appropriately in accordance with the traffic situation. Such an optimization of the control parameters in accordance with continuously changing traffic situation of the elevator system has conventionally been impossible.
Also, because the evaluation characteristics for the elevator car allocation control varies widely depending on various characteristics of each building, such as a type of usage and a type of tenant, so that the evaluation characteristics have to be selected in accordance with such characteristics of each building, an automatic setting of the evaluation characteristics has conventionally been impossible. Conventionally, the evaluation characteristics are selected by each building's administrator, and then numerous simulations are performed in order to determine the appropriate control parameters before the actual use of the elevator system begins. Thus procedure requires an enormous number of simulations to be performed, and moreover, the results of such simulations are still not capable of reflecting all the characteristics of each elevator system, such that it has been possible that the intended efficiency and speediness may not be obtained by the selected control parameters.